Interesting things.
Shift Insert does work when editing menus
This works,
&SDK Help,F:\H2Viewer\H2Viewer.exe
But these don't,
&16Bit, f:\16bit\tal.bat {b}
&When, f:\16bit\XLATB.EXE
Remove the space after the comma - it's done in a hacky way, such that it just copies all characters after the comma (including the first space) and then complains when it can't find the file that starts with a space.